Process of re-forming natural gas



March 21, 1933.

' A. YUNKER PROCESS OF- RE-FORMING NATURAL GAS Filed July 8, 1930 gwpmtob NNN..

umn..

LES@

Sauk. w w.

Patented Mar; 21, 1933 UNITI-:D STATES 'PATENT oFFlcE .TAnEsAY-UNRER, or Loursvmn, xRNTucRY, A'ssIeNoR 'ro NATURAL GAS mRoGRN .coRroRA'rIoN or NEW vom; N. Y., A.ooRroRAT1oN or DELAWARE PRooEss. on n n-rome NATURAL GAS Appunti@ mea myn, leso. serial' No. 466,559.

It is not uncommon in cities in the natural gas districts that the supply of natural gas available is insuiiicient to meet the demand at all times. Under such circumstances it `i is necessary to provide an auxiliary supply of manufactured gas which may bemixed with the available natural gas to make up a sufficient bulk of gas to meet the peak demand. Also under some circumstancesit is ,necessary or desirable to'suppl7 a consumer 4'with a gas of lower calorific va ue than pur'e natural gasv which may be done also by blending a manufactured gas of relatively lower calorific value with the natural gas.

The 'gas to be blended with the natural gas may be producer gas, blue water-A gas, -car,-

buretted water gas or some other type of gasz for instance a gas made by the decomposltion or partial combustion of the natural gas itself and it is 'customary for natural gas distributors to maintain a plant for the manufacture of artificial gas to supplement the naturalgas supply or tmodify it to meet the demands of the consumer. Such a plant,

25 as will be apparent, normally may be idle a large l portion ofthe time and its cost of maintalnence is therefore very high as comvpared with the quantity of gas produced by it,

In supplementing ya natural vgas Supply with manufactured gas and particularly when the amount of manufactured gas added to the natural .gas varies,'the character of the manufactured gas is quite important i. e:

^it is essential that the resulting blended gas shall not have burning characteristics so different from ithe normalgas supply as to cause the gas burning equipment of the consumer of the gas to function improperly. 40 Factors to be considered in this connection lare -the specific gravit and ame propogation rate of the manu actured gas. In general a hydrogen content in the manufactured gas, due to its low specific gravity and high dame propogation rateds of value because these characteristics 'offset the effect of heavy inert",v ases and slow burning relatively heavy ydrocarbons, for example producer gas or carburetting a ents which are frequently also introduce in to the blended gas inY rder to provide the necessary bulk and/or calorific value. v 'An .object ofhe present invention is -to provide a. process which Ameets the above mentioned requirements. The process of my invention is capable of being carried out in certain vtypes of the.v customary supplementary gas manufacturing equipment with only minor and relatively inexpensive modification, which apparatus may theefore be used part of the time in carrying out my process and at other times, if desired, for

themanufacture of theparticular kindof artificial gas for which it was designed.

-My process may serve to convert the natural gas into a manufactured as of up to approximately double the 'vo uniev of'l the natural gas which manufactured gas is capable of use as fuel directly or `for blending with natural gas and thus mayv itself under circumstances quite frequently encountered serve to provide the excess volume of gas necessary to meet the peak demand.l It yields a as fof high h dro en content which is a mirably suitedv or'b ending pur- 75 4poses andalso a substantial amount of sal- 'able carbon black which Vmateriallyoffsets the cost Nof operation. At times when the process is not called upon for supplementing the normal natural gas su ply and an excess of natural gas 1s available it` may be operated to produce' carbon black or industrial hydrogen or both or vto produce combustible gas' having special characteristics for certain :industrial requirements and carbon black as `a by-product. From the fore oing itwill be seen that due to 'the lexi ility of the process it' is admirably adapted to the varied conditions and requlrements of the gas utility business in adminute.

dition to producing a blendable gas, which due to its high hydrogen content is -admirably suited for blending purposeshand carbon black as a by-product so that the net 5- cost of the gas produced is less than for gas or similar quality made fore used methods. Y v

The accompanying drawingl is a diagrammatic illustration in front elevation of by the heretoone arrangement of apparatus suitable for carrying out the process.

Referring to the drawing l. represents a standard water gas generator provided with inlets 2 and 3 for the introduction of gas,

steam and air into the generator,d above and below the fuel bed and outlets 4 and' 5 for the removal of gaseous products carrylng carbon black in suspension for the generator above and below the fuel bed. For sim- I plicity, the ,actual construction of the ap-` paratus which iswell known and the piping and valves for the introduction of a1r,rgas and steam and the withdrawal of gaseous products which readily can be providedare ,25 not illustrated. Pipes 4 and 5 deliver into @and maintained and Aprovided with means for the introduction and withdrawal of gases. It is further to be Aunderstood that the invention is not limited to any particular method of or apparatus for the treatm mentof the gases leaving the generator for the recovery of carbon black, the apparatus illustrated and described herein being merely one form of apparatus suitable for carrying out the process of the invention.

The conduit 6 delivers into a cooler 8 (which might be replaced by heat exchanging apparatus) in which the gases are sprayed with water to cool them .to a` temperature suitable for the subsequent treatment, .say

.flo to about 400 F. The gases then pass through the electrostatic precipitator 9 and th cycloney device 10 both` of conventional design, then through the -oil scrubberl 11 and the water scrubber 12 to storage,

utilization or waste.'

A typical procedure is as follows: Using a nine foot generator with a fuel bed 8 feet deep, air is blasted for 3 minutes, the blast gases being wasted during the rst y21A minutes and saved during the last 1% The fuel bed of coke is then subjected to a short steam purge, for instance about 1/2 minute, the resulting water gas belng saved after which a gas run of about 1000 cubic feet per minute for about 10 minutes is made, the resulting gases bein saved. v All of the gases passed through the uel bed 'or only the gases produced pduring the gas In a specific instance yrequiring the admixture of equal parts of the manufactured Jgas and natural gas to produce a. y550 B. t. u. gas, it wasfound possible to reduce the cost ofthe resultant gas 50% as compared with gas of equal heat value prepared `by blending natural gas with blue water gas. The process is subject to great variation de ending upon various conditions which a ect the results obtained and the specic object sought. The type and size of the generator, composition of the natural gas, composition of the gas desired, kind and yield of carbon black desired, and kind o'f coke available may necessitate certain modifications of procedure suchl as the thickness of the fuel bed, thesize of the coke and the` rate and periods of running on air, steam and natural gas. To produce a gas of highsheat value, e. gi, by limiting the cracking of the hydrocarbon, the period of contactA of the gas with the. fuel bed may be limited by passing the gas at a rapid rate, or using a thinner fuel bed, or both, or by` running the gas for a-longer period, or with the fuel bed at a lower temperature, whereas to produce a gas or high hydrogen content and low heat value the conditions generally arev reversed, i. e., the conditions are adjusted so as to afford a relatively long contact between the gas and the coke at a high temperature. Generally a Atemperature above 1200,o C. or in the range 1200 to 14.00 C. is employed. To maintain the fuel bed continuously ,at optimum operating condition, the air and gas runs may be reversed from time 'to time or periodically or split, that is part ofthe run may be 1n one direction and the remainder of the run in the oppo-4 Jsite direction through the fuel bed. Itis .also desirable occaslonally or periodically, l

say every fourth or fifth run to substitute for a gas run a steam run enerally of shorter duration,to' condition-t e fuel bed. The steam run seems to clear the fuel bed of deposited carbon .and to prevent caking.. In any event a steam runl generally results in' a reduction. of the resistance of the fuel 'bed to the How of gas through it, as well as a reduction in coke consumption. The

` steam purge serves to clear the roducer of unconsumed air and thus to avoi explosions upon the introduction of gas.

A possible variation of the above described procedure is to introduce steam into the generator along with the natural as thereby producing directly a combinatlon of Water gas and cracked natural gas suitable for use as fuel or for blending purposes.

Under certain circumstances a supply of so-called refinery gases, which are mixtures of hydrocarbons, carbon oxides, nitrogen,

etc., resulting fromV the refining or cracking of petroleum, are available for utility use. `These gases are quite similar in chemical composition and can be treated in the same manner for the production of a gas K of high hydrogen content and carbon black,

as a bye-product, as natural gas. Such gases normally are 4of high heat value and speciic gravity, both of which may be reduced to correspond with that of natural gas or of a manufactured gas with which they are to be blended or for which they are to besubstituted.

In the appended claim natural gas embraces refinery gases and other gases of similar compositlon, i. e., consisting essentially of gaseous hydrocarbons as equivalents'.

I claim: y

Process of re-forming natural gas which comprises blasting a bed of coke at a temperaturel of about 1200 C., with air for about three minutes, to raise its temperature to about 1400o C., wasting the gases produced during about the first 2% minutes' of said 3 minute period and saving the ases produced during about the last W4 minute of'said 3 minute period, urging the bed of coke With steam for a out 1/2 minute, saving the'resulting gases, and then passing natural gas through the bed of coke for about 8 to 10 minutes, saving the resulting gases, purifying the saved gases and recovering carbon black therefrom and mixing the purified gases for use as fuel, vand continuously repeating the series of operations.

In testimony whereof, I aix my signature.

JAMES A. YUNKER. 

